Process of Producing Graphite Electrode

Mill, Mix & Forming

Premium quality calcined coke is crushed,screened, and hot-blended with pitch in controlled proportions. The resulting plastic mass is extruded through a forming press and cut into specified lengths before being water-cooled in a temperature-controlled bath.

Process of Producing Graphite Electrode

Baking

Green electrodes are placed in large canscalled saggers and baked to over 800° C (1400° F) in specially designed,computer-controlled furnaces. It takes 1-to-2 weeks to carbonize the pitch depending upon the size of the electrodes being made. After cooling, the carbon electrodes are cleaned, inspected, and sample-tested.

Process of Producing Graphite Electrode

Impregnation

Next, the baked electrodes are impregnated with a special pitch to give them the higher density, mechanical strength, and electrical conductivity they will need to withstand the severe operating conditions inside our customers' electric arc furnaces.

Process of Producing Graphite Electrode

Rebake

A second baking cycle, or "rebake", is required to carbonize the pitch impregnation and to drive off any remaining volatiles. Rebake temperatures reach almost 750°C (1300° F).

Process of Producing Graphite Electrode

Graphitizing

The rebaked carbon electrodes are further processed in long electric resistance furnaces. Laid end-to-end, or“longitudinally,” the electrodes are heated to over 3000° C (5000° F). This ultra-high temperature restructures the carbon to its crystalline form—graphite. Then the electrodes are once again cooled, cleaned, inspected, and sample-tested.

Process of Producing Graphite Electrode

Machining

In Machining, the electrodes outer dimension are turned to its finished dimension. The two end faces are also machined to tolerance and given threaded sockets. The sockets acceptdouble-tapered, machine-threaded graphite connecting pins which allow our customers to join electrodes together into columns.

Process of Producing Graphite Electrode


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